Return-Path: Received: from rly-df10.mx.aol.com (rly-df10.mail.aol.com [172.19.156.23]) by air-df06.mail.aol.com (v124.15) with ESMTP id MAILINDF064-57e4a8bd93d246; Wed, 19 Aug 2009 06:51:45 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-df10.mx.aol.com (v124.15) with ESMTP id MAILRELAYINDF101-57e4a8bd93d246; Wed, 19 Aug 2009 06:51:43 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1MdikK-000597-Gt for rs_out_1@blacksheep.org; Wed, 19 Aug 2009 11:50:24 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1MdikK-00058y-2Z for rsgb_lf_group@blacksheep.org; Wed, 19 Aug 2009 11:50:24 +0100 Received: from smtp142.mail.mud.yahoo.com ([209.191.107.125]) by relay3.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1MdikF-0000U9-4i for rsgb_lf_group@blacksheep.org; Wed, 19 Aug 2009 11:50:19 +0100 Received: (qmail 3883 invoked from network); 19 Aug 2009 10:50:11 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=6AmFL2XrBj+kuzVTWiYOOd2FIS2rn40IhWFTNBpM+yPC+4xzyCBUCfCDNfU2nDdc0wwGjoHBOzLLUFaP5N70p/7nuJjMsZ78zZPyrLJZIj/tCSyoHg2pVV+jnzddXMmDU81iMJbt4HtxJ0QIfKJ9AMUWYg54K5UOHh/wKcPkhQI= ; Received: from unknown (HELO lindavideo) (ken.h.wright@86.134.96.50 with login) by smtp142.mail.mud.yahoo.com with SMTP; 19 Aug 2009 10:50:11 -0000 X-Yahoo-SMTP: APVNTmmswBB1ajQe0.MR1eIpHqOdoGKpEnK7HtPhl2t5AIcci3nTdw-- X-YMail-OSG: T1mSxoUVM1mbOM8bYr9AKWV_MUBjDszAYMwjY_Cq8F.YotqmbxHAdujwOySxf0vrKwBTH_GPZ7wTSFbTAGbl26GGLYSqesrjpoZfhUs7MznQ5CotvmrK6sohNT3pfKlnfkYakEFDRW8lnlTQ1h50lXNdN.bIZCRtxmX67jeOU9Vy9jgqcjzp1XgpI8ySJtipft_7MjvecG50z2EtIDaxWyOVEMgTcxH1l8IJQRrJL338pA9GyI0shs0cXCKQsr3MzPlORBR2hByLILfKSx4eFyFeXIsgH6JDwVj7dhrW0lldvPRoqxxSRjobt78lR5cimUfAh0c_7xOG0yE0Jpk2sgmwfvHMpcsK X-Yahoo-Newman-Property: ymail-3 Message-ID: From: "Ken" To: References: <20090818201756.306460@gmx.net> Date: Wed, 19 Aug 2009 11:50:09 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 DomainKey-Status: good (testing) Subject: LF: Re: 500kHz qrg range Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=FORGED_MUA_OUTLOOK autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-AOL-IP: 193.82.116.20 Hi Dennis. I manage quite well with a simple two reasonator filter with tapped capacitors for input and output impedance matching, response as follows, centre 501.9, 3dB, 495.8 & 508.26, 6dB, 492.77 & 511.3, 24dB, 468.43 & 532.52, 30dB, 453.97 & 543.25. 73 Ken M0KHW ----- Original Message ----- From: "Dennis" To: Sent: Tuesday, August 18, 2009 9:17 PM Subject: LF: 500kHz qrg range > > Hi! > > For some hours now I'm sitting in front of the computer, modelling a new > and of course much much nicer :) preselector-filter for 500kHz. With a > 3-inductor nodal capacitor-coupled bandpass, a 12kHz passband seems to be > a good tradeoff beetween insertation loss (2-3db), passband ripple (1db) > and shape (-24db at 518KHz, -43db at 531kHz). > > So far I haven't noticed any transmissions below 500.000kHz (SK6RUD) and > above abt. 507kHz (Gus' SSB-Tests). > > So I ask myself and now You :) , would You say it's important to keep the > full rx range from 495kHz to 510kHz and pay the price of a worse stopband > attenuation, or do You think, it's unlikely to hear any transmission at > the band corners? > > vy73 > Dennis > > > > > -- > Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3 - > sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser >